A top General Services Administration official who was in charge of organizing a lavish Las Vegas conference that’s drawn congressional and taxpayer fire repeatedly invoked his Fifth Amendment right against self-incrimination Monday on Capitol Hill.

During Monday’s hearing, Jeff Neely, refused to answer several questions from House Oversight and Government Committee chairman Darrell Issa (R-Calif.), including rudimentary questions such as his official title at GSA and whether he was currently employed at the agency.

Issa also asked Neely if he attended the Las Vegas conference, whether he approved funding for it, the size of the event’s original budget, and if he were prepared to answer any questions related to the junket that’s now become an icon of federal waste.

“On the advice of counsel, I respectfully decline,” Neely replied.

Issa said this was the first time that a person called to testify before his committee refused to testify.

Neely was seated in the middle of five people at the hearing connected to the spending scandal, but left the room soon after he pleaded the Fifth. The career civil servant, who could also be facing a Justice Department probe into allegations of theft and contracting violations, told investigators that he felt he didn’t need to get competitive bids because he was paying for quality, according to the Washington Post.

Before Neely left, however, Democratic and Republican lawmakers lambasted the agency official for his role planning the conference that squandered hundreds of thousands of taxpayer funds.

Rep. Elijah Cummings (D-Md.) ripped Neely and his wife Deb – who documents show was involved in some of the planning for the conference – for living like “agency royalty” who funded their “lavish lifestyle” at the taxpayers’ expense.

“They disregarded one of the most basic tenets of government service – it’s not your money; it’s the taxpayers’ money,” said Cummings, the top Democrat on the Oversight committee. “I want to know how we can recoup these funds, including from Mr. Neely and other GSA employees personally.”

“You know, Alexander Graham Bell has this marvelous invention called a telephone,” said Rep. Trey Gowdy (R-S.C.) sarcastically. “Better yet, a videoconference … the notion that you have to spend $800,000 to exchange ideas is laughable.”

Another person seated alongside Neely was former GSA administrator Martha Johnson, who apologized for the excessive costs for the 2010 Western Regions Conference that occurred under her watch.

She testified that while the biennial GSA conference was once “economical” and “straightforward” it had become a “raucous, extravagant, arrogant, self-congratulatory event that ultimately belittled federal workers.”

“I am extremely aggrieved by the gall of a handful of people to misuse federal tax dollars, twist contracting rules and defile the great name of the General Services Administration,” said Johnson, who resigned shortly after the details of the conference’s expenses were revealed. But “as the head of the agency, I am responsible … I will mourn for the rest of my life the loss of my appointment.”

But congressional Republicans repeatedly grilled Johnson over her handling of Neely’s conduct, particulary over the fact that Neely was awarded a $9,000 bonus even though GSA officials were aware of preliminary results of an investigation into the conference spending.

Johnson said Neely got the bonus because he had been recommended by another supervisor to receive one — but that explanation didn’t appease lawmakers.

“Why not fire Mr. Neely?” asked Rep. Jason Chaffetz (R-Utah). “You know, he’s still being paid by taxpayers … so my question is to the chief of staff, why is he still an employee of the United States government? What does it take to actually get fired from the GSA?”

Issa also questioned why it took nearly a year for the details about the conference’s excessive spending to come to light and for disciplinary actions to take place, saying lawmakers on the committee believed that to be “outrageous.”

The House hearing Monday launched a weeklong congressional inquiry into how exactly the General Services Administration – a once-obscure agency charged with managing federal property – spent more than $800,000 for the Las Vegas conference in October 2010 for 300 employees.

The controversy over excessive government spending at a time of fiscal belt-tightening fueled extensive public outrage when an April 2 report from the GSA’s inspector general detailed the $822,751 of taxpayer dollars spent for the conference at the M Resort Spa Casino in Las Vegas.

The inspector general found that IG found that “many of the expenditures on this conference were excessive and wasteful and that in many instances GSA followed neither federal procurement laws nor its own policy on conference spending.” Examples of such expenditures included $75,000 for a bicycle-building exercise and $3,200 for a mind-reader.

The embarrassing episode led to the resignation of Johnson, and several other top GSA officials were either fired or placed on administrative leave.

David Foley, another GSA official who appeared in a video that appeared to make light of the excessive conference spending, also apologized to lawmakers. Foley, who said Monday that he thought much of the conference’s costs was being paid with private funds, was placed on administrative leave after the video surfaced.

“I did not intend to condone the role of excessive spending,” Foley told the committee. Like a comedic roast, “I attempted to make a joke.”

Democrats have tried to highlight the fact that costs for the biennial conference jumped under previous administrations; for example, the 2006 GSA Western Regions Conference in Oklahoma City cost $323,855 and the 2008 conference in New Orleans cost $655,025.

Issa speculated earlier Monday that “perhaps billions of dollars” could have been spent for the conferences – a pattern of spending that could have started under the George W. Bush administration.

“Wasteful spending is a problem that transcends multiple administrations and multiple Congresses,” Issa said before the hearing. “But it’s incumbent on the present administration and the current Congress to mandate a culture that prevents this type of waste and mismanagement, no matter what happened before them.”

Three other congressional hearings – one in the House and two in the Senate – are scheduled for this week.